private void HandOver(SubstreamHandler handler)
{
if (IsClosed(_stage._out))
{
CompleteStage();
}
else
{
_substreamSource = new SubSourceOutlet <T>(this, "SplitSource");
_substreamSource.SetHandler(handler);
_substreamCancelled = false;
SetHandler(_stage._in, handler);
SetKeepGoing(handler.HasInitialElement);
if (IsAvailable(_stage._out))
{
Push(_stage._out, Source.FromGraph(_substreamSource.Source));
ScheduleOnce(SubscriptionTimer, _timeout);
_substreamPushed = true;
}
else
{
_substreamPushed = false;
}
}
}
public override void OnPush()
{
var elem = _logic.Grab(_logic._stage._in);
try
{
if (_logic._stage._predicate(elem))
{
var handler = new SubstreamHandler(_logic);
CloseThis(handler, elem);
_logic.HandOver(handler);
}
else
{
// Drain into the void
if (_logic._substreamCancelled)
{
_logic.Pull(_logic._stage._in);
}
else
{
_logic._substreamSource.Push(elem);
}
}
}
catch (Exception ex)
{
OnUpstreamFailure(ex);
}
}
public void OnPush()
{
var handler = new SubstreamHandler(this);
var elem = Grab(_stage._in);
if (_stage._decision == Split.SplitDecision.SplitAfter && _stage._predicate(elem))
{
Push(_stage._out, Source.Single(elem));
}
// Next pull will come from the next substream that we will open
else
{
handler.FirstElement = elem;
}
HandOver(handler);
}
public Logic(Split <T> stage) : base(stage.Shape)
{
_stage = stage;
SetHandler(stage._out, onPull: () =>
{
if (_substreamSource == null)
{
Pull(stage._in);
}
else if (!_substreamPushed)
{
Push(stage._out, Source.FromGraph(_substreamSource.Source));
ScheduleOnce(SubscriptionTimer, _timeout);
_substreamPushed = true;
}
}, onDownstreamFinish: () =>
{
// If the substream is already cancelled or it has not been handed out, we can go away
if (!_substreamPushed || _substreamCancelled)
{
CompleteStage();
}
});
// initial input handler
SetHandler(stage._in, onPush: () =>
{
var handler = new SubstreamHandler(this);
var elem = Grab(_stage._in);
if (_stage._decision == Split.SplitDecision.SplitAfter && _stage._predicate(elem))
{
Push(_stage._out, Source.Single(elem));
}
// Next pull will come from the next substream that we will open
else
{
handler.FirstElement = elem;
}
HandOver(handler);
}, onUpstreamFinish: CompleteStage);
}
private void CloseThis(SubstreamHandler handler, T currentElem)
{
var decision = _logic._stage._decision;
if (decision == Split.SplitDecision.SplitAfter)
{
if (!_logic._substreamCancelled)
{
_logic._substreamSource.Push(currentElem);
_logic._substreamSource.Complete();
}
}
else if (decision == Split.SplitDecision.SplitBefore)
{
handler.FirstElement = currentElem;
if (!_logic._substreamCancelled)
{
_logic._substreamSource.Complete();
}
}
}